1. Field of the Invention
The invention relates to electric light strings.
2. Description of Related Art
Light strings are widely used for decorative purposes, especially for holiday lighting. Light strings refer to lights connected electrically in a series. Generally, a light string includes more than 10 lights, and is powered by mains electricity, such as 110V AC mains electricity. Thus, a voltage supplied on each light is 1.5V to 12V. When the light string is powered on, a surge current may be generated and may burn out the light bulb mounted in a lamp base. In the conventional light strings, when the filament of the light bulb fails and the bulb remains in the string, or when the bulb is removed from its socket for replacement, the closed path for the flow of electrical current is interrupted and the remainder of the lamps in the string will no longer be illuminated.
U.S. application Ser. No. 13/915,668, filed on Jun. 12, 2013, discloses a light string, which includes a number of lights. The lights are electrically connected in series and powered by an AC power supply. At least one capacitor is connected in parallel to one of the lights. Each light or a part of lights of the light string of the present invention is electrically connected in parallel to a capacitor. When the light string is powered on, the capacitor is charged and absorbs a surge current which may occur. Thus, the voltage dropped on each light rises slowly and the lights are safe. The capacitor also performs power compensation and electrical connection. When the filament of the light bulb fails and the bulb remains in the light string, or when the bulb is removed from its socket for replacement, the closed path for flow of electrical current is still closed.
U.S. application Ser. No. 14/747,584, filed on Jun. 23, 2015, discloses a light string, which includes a plurality of bulbs connected in series and powered by an AC power supply. Each bulb is connected in parallel with a capacitor, the capacitor is a polarized electrolytic capacitor, and capacitance of the capacitor is 47 uF-120 uF; a rated voltage of the capacitor is higher than a rated voltage of the bulb, and the rated voltage of the capacitor is 16V-100V; and when one bulb in the light string fails, the capacitor that is connected in parallel with the failed bulb operates normally; a positive plate and a negative plate of the capacitor connected in parallel with said each bulb are both covered with an oxide film insulating layer; when the light string is powered on, the oxide film insulating layer prevents breakdown and short circuit of the capacitor connected in parallel with said each bulb under the influence of a reverse voltage of the AC power.